FreeBSD/Linux Kernel Cross Reference
sys/sys/linker.h
1 /*-
2 * Copyright (c) 1997-2000 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29 #ifndef _SYS_LINKER_H_
30 #define _SYS_LINKER_H_
31
32 #ifdef _KERNEL
33
34 #include <machine/elf.h>
35 #include <sys/kobj.h>
36
37 #ifdef MALLOC_DECLARE
38 MALLOC_DECLARE(M_LINKER);
39 #endif
40
41 struct mod_depend;
42
43 /*
44 * Object representing a file which has been loaded by the linker.
45 */
46 typedef struct linker_file* linker_file_t;
47 typedef TAILQ_HEAD(, linker_file) linker_file_list_t;
48
49 typedef caddr_t linker_sym_t; /* opaque symbol */
50 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */
51 typedef int (*linker_function_name_callback_t)(const char *, void *);
52
53 /*
54 * expanded out linker_sym_t
55 */
56 typedef struct linker_symval {
57 const char* name;
58 caddr_t value;
59 size_t size;
60 } linker_symval_t;
61
62 struct common_symbol {
63 STAILQ_ENTRY(common_symbol) link;
64 char* name;
65 caddr_t address;
66 };
67
68 struct linker_file {
69 KOBJ_FIELDS;
70 int refs; /* reference count */
71 int userrefs; /* kldload(2) count */
72 int flags;
73 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */
74 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */
75 char* filename; /* file which was loaded */
76 int id; /* unique id */
77 caddr_t address; /* load address */
78 size_t size; /* size of file */
79 int ndeps; /* number of dependencies */
80 linker_file_t* deps; /* list of dependencies */
81 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */
82 TAILQ_HEAD(, module) modules; /* modules in this file */
83 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */
84 };
85
86 /*
87 * Object implementing a class of file (a.out, elf, etc.)
88 */
89 typedef struct linker_class *linker_class_t;
90 typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
91
92 struct linker_class {
93 KOBJ_CLASS_FIELDS;
94 TAILQ_ENTRY(linker_class) link; /* list of all file classes */
95 };
96
97 /*
98 * Function type used when iterating over the list of linker files.
99 */
100 typedef int linker_predicate_t(linker_file_t, void *);
101
102 /*
103 * The "file" for the kernel.
104 */
105 extern linker_file_t linker_kernel_file;
106
107 /*
108 * Obtain a reference to a module, loading it if required.
109 */
110 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo,
111 linker_file_t* _result);
112
113 /*
114 * Release a reference to a module, unloading it if there are no more
115 * references. Note that one should either provide a module name and
116 * optional version info or a linker file, but not both.
117 */
118 int linker_release_module(const char *_modname, struct mod_depend *_verinfo,
119 linker_file_t _file);
120
121 /*
122 * Iterate over all of the currently loaded linker files calling the
123 * predicate function while the function returns 0. Returns the value
124 * returned by the last predicate function.
125 */
126 int linker_file_foreach(linker_predicate_t *_predicate, void *_context);
127
128 /*
129 * Lookup a symbol in a file. If deps is TRUE, look in dependencies
130 * if not found in file.
131 */
132 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name,
133 int _deps);
134
135 /*
136 * Lookup a linker set in a file. Return pointers to the first entry,
137 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {}
138 * void *start is really: "struct yoursetmember ***start;"
139 */
140 int linker_file_lookup_set(linker_file_t _file, const char *_name,
141 void *_start, void *_stop, int *_count);
142
143 /*
144 * Functions soley for use by the linker class handlers.
145 */
146 int linker_add_class(linker_class_t _cls);
147 int linker_file_unload(linker_file_t _file, int flags);
148 int linker_load_dependencies(linker_file_t _lf);
149 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls);
150
151 /*
152 * DDB Helpers, tuned specifically for ddb/db_kld.c
153 */
154 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
155 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
156 long *_diffp);
157 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
158
159
160 /* HWPMC helper */
161 void *linker_hwpmc_list_objects(void);
162
163 #endif /* _KERNEL */
164
165 /*
166 * Module information subtypes
167 */
168 #define MODINFO_END 0x0000 /* End of list */
169 #define MODINFO_NAME 0x0001 /* Name of module (string) */
170 #define MODINFO_TYPE 0x0002 /* Type of module (string) */
171 #define MODINFO_ADDR 0x0003 /* Loaded address */
172 #define MODINFO_SIZE 0x0004 /* Size of module */
173 #define MODINFO_EMPTY 0x0005 /* Has been deleted */
174 #define MODINFO_ARGS 0x0006 /* Parameters string */
175 #define MODINFO_METADATA 0x8000 /* Module-specfic */
176
177 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */
178 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */
179 #define MODINFOMD_SSYM 0x0003 /* start of symbols */
180 #define MODINFOMD_ESYM 0x0004 /* end of symbols */
181 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */
182 /* These values are MD on these two platforms */
183 #if !defined(__sparc64__) && !defined(__powerpc__)
184 #define MODINFOMD_ENVP 0x0006 /* envp[] */
185 #define MODINFOMD_HOWTO 0x0007 /* boothowto */
186 #define MODINFOMD_KERNEND 0x0008 /* kernend */
187 #endif
188 #define MODINFOMD_SHDR 0x0009 /* section header table */
189 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */
190
191 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */
192
193 #ifdef _KERNEL
194 #define MD_FETCH(mdp, info, type) ({ \
195 type *__p; \
196 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \
197 __p ? *__p : 0; \
198 })
199 #endif
200
201 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */
202
203 #ifdef _KERNEL
204
205 /*
206 * Module lookup
207 */
208 extern caddr_t preload_metadata;
209 extern caddr_t preload_search_by_name(const char *_name);
210 extern caddr_t preload_search_by_type(const char *_type);
211 extern caddr_t preload_search_next_name(caddr_t _base);
212 extern caddr_t preload_search_info(caddr_t _mod, int _inf);
213 extern void preload_delete_name(const char *_name);
214 extern void preload_bootstrap_relocate(vm_offset_t _offset);
215
216 #ifdef KLD_DEBUG
217
218 extern int kld_debug;
219 #define KLD_DEBUG_FILE 1 /* file load/unload */
220 #define KLD_DEBUG_SYM 2 /* symbol lookup */
221
222 #define KLD_DPF(cat, args) \
223 do { \
224 if (kld_debug & KLD_DEBUG_##cat) printf args; \
225 } while (0)
226
227 #else
228
229 #define KLD_DPF(cat, args)
230
231 #endif
232
233 typedef Elf_Addr elf_lookup_fn(linker_file_t, Elf_Size, int);
234
235 /* Support functions */
236 int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu);
237 int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu);
238 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx);
239 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx);
240
241 int elf_cpu_load_file(linker_file_t);
242 int elf_cpu_unload_file(linker_file_t);
243
244 /* values for type */
245 #define ELF_RELOC_REL 1
246 #define ELF_RELOC_RELA 2
247
248 #endif /* _KERNEL */
249
250 struct kld_file_stat {
251 int version; /* set to sizeof(linker_file_stat) */
252 char name[MAXPATHLEN];
253 int refs;
254 int id;
255 caddr_t address; /* load address */
256 size_t size; /* size in bytes */
257 };
258
259 struct kld_sym_lookup {
260 int version; /* set to sizeof(struct kld_sym_lookup) */
261 char *symname; /* Symbol name we are looking up */
262 u_long symvalue;
263 size_t symsize;
264 };
265 #define KLDSYM_LOOKUP 1
266
267 /*
268 * Flags for kldunloadf() and linker_file_unload()
269 */
270 #define LINKER_UNLOAD_NORMAL 0
271 #define LINKER_UNLOAD_FORCE 1
272
273 #ifndef _KERNEL
274
275 #include <sys/cdefs.h>
276
277 __BEGIN_DECLS
278 int kldload(const char* _file);
279 int kldunload(int _fileid);
280 int kldunloadf(int _fileid, int flags);
281 int kldfind(const char* _file);
282 int kldnext(int _fileid);
283 int kldstat(int _fileid, struct kld_file_stat* _stat);
284 int kldfirstmod(int _fileid);
285 int kldsym(int _fileid, int _cmd, void *_data);
286 __END_DECLS
287
288 #endif
289
290 #endif /* !_SYS_LINKER_H_ */
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